JBossContextConfig.beforeLoadOnStartup throws NullPointerException

Issue

• JBossContextConfig.beforeLoadOnStartup throws a NullPointerException upon application deployment:

DEBUG [org.jboss.as.web.security] (ServerService Thread Pool -- 22) Failed to determine servlet: java.lang.NullPointerException
    at org.jboss.as.web.deployment.JBossContextConfig.beforeLoadOnStartup(JBossContextConfig.java:667) [jboss-as-web-7.5.1.Final-redhat-3.jar:7.5.1.Final-redhat-3]
    at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:178) [jbossweb-7.5.9.Final-redhat-1.jar:7.5.9.Final-redhat-1]
    at org.jboss.as.web.deployment.JBossContextConfig.lifecycleEvent(JBossContextConfig.java:260) [jboss-as-web-7.5.1.Final-redhat-3.jar:7.5.1.Final-redhat-3]
    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:115) [jbossweb-7.5.9.Final-redhat-1.jar:7.5.9.Final-redhat-1]
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:3592) [jbossweb-7.5.9.Final-redhat-1.jar:7.5.9.Final-redhat-1]
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:3802) [jbossweb-7.5.9.Final-redhat-1.jar:7.5.9.Final-redhat-1]
    at org.jboss.as.web.deployment.WebDeploymentService.doStart(WebDeploymentService.java:163) [jboss-as-web-7.5.1.Final-redhat-3.jar:7.5.1.Final-redhat-3]
    at org.jboss.as.web.deployment.WebDeploymentService.access$000(WebDeploymentService.java:61) [jboss-as-web-7.5.1.Final-redhat-3.jar:7.5.1.Final-redhat-3]
    at org.jboss.as.web.deployment.WebDeploymentService$1.run(WebDeploymentService.java:96) [jboss-as-web-7.5.1.Final-redhat-3.jar:7.5.1.Final-redhat-3]
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [rt.jar:1.8.0_66]
    at java.util.concurrent.FutureTask.run(FutureTask.java:266) [rt.jar:1.8.0_66]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [rt.jar:1.8.0_66]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [rt.jar:1.8.0_66]
    at java.lang.Thread.run(Thread.java:745) [rt.jar:1.8.0_66]
    at org.jboss.threads.JBossThread.run(JBossThread.java:122)

• This is seen for applications that have a servlet mapping without a class:

  <servlet>
    <servlet-name>error.login</servlet-name>
    <jsp-file>/jsp.jsp</jsp-file>
  </servlet>